Probing the Solution-Phase Dynamics of l3-Iodanes and Relation to Reactivity

在这个项目中，波特兰州立大学化学系的大卫·斯图尔特教授正在研究有机碘化学试剂，该项目由化学系化学结构、动态和机理B计划资助。这项研究的目标是了解分子结构和反应介质如何相互作用，以影响这些化合物在化学反应中的整体行为。该项目位于物理和合成有机化学的交界处，最终应用于健康、农业和技术；它非常适合在高等教育环境中培养科学家。波特兰州立大学是一所多元化的大学，在培养代表不足的理科学生方面处于有利地位。斯图尔特教授的团队与精细化学工业之间的合作将有助于更快地将基础发现转化为更广泛的科学界的应用。高价碘试剂在化学合成中经常用作催化剂、引发剂、试剂和氧化剂，因为它们与已建立的和新兴的反应范例很好地结合在一起，如离子反应、金属介导/催化反应和自由基反应。静电相互作用是高价碘化合物扩展配位中键的一个组成部分，假设它们发生在聚集和Lewis酸碱化学过程中，直接影响反应活性和应用。该项目的目标是揭示影响高价碘化合物溶液-相相互作用的结构和溶剂效应，并与反应化学有明确的联系。这是通过合成设计的单芳基和二芳基碘化合物的库，进行核磁共振和质谱学滴定实验，通过非线性回归将滴定数据与结合模型拟合，以及分析线性自由能关系和反应动力学来实现的。通过1)量化和利用芳基(2，4，6-三甲氧基苯基)碘盐及其相关衍生物的Lewis酸度，2)评估这些盐的溶液相聚集对反应性和选择性的影响，以及3)芳基碘烷与Bronsted-Lowry酸的活化，将获得对高价碘在溶液相中行为的更深层次的了解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In this project, funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor David Stuart of the Department of Chemistry at Portland State University is studying organoiodine chemical reagents. The goal of this research is to understand how the molecular structure and the reaction medium interact to influence overall behavior of these compounds in chemical reactions. The project lies at the interface of physical and synthetic organic chemistry with eventual applications in health, agriculture, and technology; it is well-suited to the training of scientists in a higher-education setting. Portland State University is a diverse institution and is well-positioned for training underrepresented students in sciences. Collaboration between the Professor Stuart's group and the fine-chemical industry will facilitate a more rapid translation of fundamental discoveries into applications by the broader scientific community.Hypervalent iodine reagents are routinely used as catalysts, initiators, reagents, and oxidants in chemical synthesis because they integrate well with established and emerging reactivity paradigms such as ionic, metal-mediated/catalyzed, and radical reactions. Electrostatic interactions are an integral component of bonding in the expanded coordination of hypervalent iodine compounds and the hypothesis is that they occur during aggregation and Lewis acid-base chemistry with a direct impact on reactivity and applications. The goal of this project is to unravel the structure and solvent effects that influence solution-phase interactions of hypervalent iodine compounds with a clear link to reaction chemistry. This is to be achieved by synthesizing designed libraries of monoaryl and diaryliodonium compounds, conducting nuclear magnetic resonance and mass spectrometry titration experiments, fitting titration data to binding models by non-linear regression, and analyzing linear Free-energy relationships and reaction kinetics. A deeper understanding of the behavior of hypervalent iodine in the solution phase will be obtained by 1) quantifying and exploiting the Lewis acidity of aryl(2,4,6-trimethoxyphenyl)iodonium salts and related derivatives, 2) assessing the influence of solution-phase aggregation of these salts on reactivity and selectivity, and 3) activation of aryl iodanes with Bronsted-Lowry acids.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.